Code Gallery - Use the codes below at the Code Entry menu:

Password: Result:

54641 1-Hit Dishonor
97831 Character Gallery
34743 Double Damage
53467 Neverending Stealth
24463 Unlimited Chi
23637 Unlimited Copper
94677 Unlimited Health
37437 Unlock all Treasure Maps

Unlockable Galleries...

Character Story Board Gallery Collect all Set Items through level 6.
Level Art Gallery Collect all Set Items through level 3.
Stroy Board Gallery Collect all Set Items through level 5.

Fight the fire machine - This is the machine you must fight in order to find Katara. Dodge the fire bending. Try running left to right, then right to left. Continue this until you see a flashing light near it, then attack it. Hit it with Aang. You may use a Chi attack but just a plain attack should work just as well, however it takes time. You will have Saka (Katara's brother) fighting with you to do double damage. Once it has around a quarter of its HP gone, the machine will start throwing fire around. Keep a safe distance from this attack. It causes no real threat to your or your partner as long as you stay as far away as possible.

Easy experience - Whenever you are in battle you can go back later to get more experience.